Two boxes are attached to opposite ends of a rope passing over a frictionless pulley as shown below. The mass of Box A is 15kg and the mass of box B is 12kg. The system is originally at rest with the bottom of box A at a height of o.85m above the floor. When the system is released, the boxes will move. Use conservation of energy to determine the speed with which Box A will contact the floor.
Ek= 1/2 mv^2/2
The Attempt at a Solution
I started off by drawing free body diagrams of each mass, one at rest, and one in motion.
For mass A:
For mass B:
I'm not sure if my original statement of Ft=Eg is accurate... and from this point on I don't know where to go.